Adding Epion integration documentation (#30724)

* Adding Epion integration documentation

* Updating release version

* Update source/_integrations/epion.markdown

Co-authored-by: c0ffeeca7 <38767475+c0ffeeca7@users.noreply.github.com>

* Update source/_integrations/epion.markdown

Co-authored-by: c0ffeeca7 <38767475+c0ffeeca7@users.noreply.github.com>

* Update source/_integrations/epion.markdown

Co-authored-by: c0ffeeca7 <38767475+c0ffeeca7@users.noreply.github.com>

---------

Co-authored-by: c0ffeeca7 <38767475+c0ffeeca7@users.noreply.github.com>

source/_integrations/epion.markdown

@@ -0,0 +1,37 @@
+---
+title: Epion
+description: Instructions on how to integrate Epion Air CO2 sensors with Home Assistant
+ha_category:
+  - Environment
+  - Sensor
+ha_release: '2024.2'
+ha_iot_class: Cloud Polling
+ha_codeowners:
+  - '@lhgravendeel'
+ha_config_flow: true
+ha_domain: epion
+ha_platforms:
+  - sensor
+ha_integration_type: integration
+---
+
+Integrates Epion Air sensors into Home Assistant.
+
+[Epion](https://www.epion.nl/) helps you provide insights into air quality, easy to use for everyone.
+
+Requires a configured Epion Air device and an Epion account with access to this device.
+
+## Prerequisites
+
+Epion API token setup.
+
+1. Login to [Epion](https://www.epion.nl/).
+2. Select [Integrations](https://epion.nl/dashboard/integrations) in the left menu.
+3. To create a new token, if you don't see one already, select **Generate new Token**.
+4. Copy your generated token. The token is a set of alphanumeric characters separated by hyphens. It starts with "a/".
+
+The Epion integration can now be activated using this API token.
+
+All connected devices will show entities for the carbon dioxide (CO2) concentration, temperature, relative humidity, and barometric pressure.
+
+{% include integrations/config_flow.md %}